The long range goal of the proposed research is to provide a thorough understanding of the complex regulation of gonadotropin and prolactin secretion by the adenohypophysis. Studies will be conducted to delineate further the pathways in the CNS involved in the regulation of these hormones, to evaluate putative transmitters involved in inducing release of the releasing and inhibiting hormones which control the release of gonadotropins and prolactin, to evaluate further the effects of steroids and other agents on the responsiveness of the pituitary to LH-releasing hormone (LRH), to study further the mechanism of action of the releasing and inhibiting hormones on the gland, and lastly to carry out further studies on the postulated FSH-releasing factor, the hypothalamic factors affecting prolactin release and a postulated inhibitor of gonadotropin release. It is hoped that the results of this research will have relevance and even direct application to population control.